1. Technical Field
The present disclosure relates generally to a molding device for forming a compact lens barrel.
2. Description of Related Art
Compact image pick-up apparatuses are used in a variety of consumer electronic devices, such as notebook computers, personal digital assistants (PDAs), and cellular telephones. The compact image pick-up apparatus includes a compact lens barrel, a number of optical lenses received in the compact lens barrel, and an image sensor. The compact lens barrel includes a light incident opening defined in the distal end thereof for allowing the outside light into the lens barrel. The compact lens barrel is usually formed by injection molding using a molding device. For forming a compact lens barrel, a very accurate molding device is demanded.
The molding device includes a first mold part and an opposite second mold part. The first and second mold parts cooperatively form a molding cavity in the shape of the compact lens barrel. The first mold part includes a concave portion, and the second mold part includes a convex portion inserted in the concave portion. The lens barrel is formed in the molding cavity. A first protrusion is formed on an end face of the convex portion, and a second protrusion is formed on an inner bottom surface of the concave portion. The first protrusion is in contact with the second protrusion for forming the light incident opening. A parting surface is formed between the end face of the convex portion and the inner bottom surface of the concave portion. A patching surface with a width greater than 0.02 millimeters (mm) is formed around the parting surface for preventing formation of burrs. However, this results in a very thin inner edge of the compact lens barrel in the light incident opening, thereby causing the inner edge become pervious to light, which may cause glare during image capture.
Therefore, there is a need for a molding device for molding a lens barrel, to overcome the above mentioned limitations.